Synchronizing circuit

ABSTRACT

A manikin synchronization system is described to cause recorded aural sounds to be coincident with mechanical motions including the effects of the breathing cycles. The synchronization system interfaces with the mechanical and audio systems in order to bring heart sounds, breathing cycles and mechanical motions into time coincidence. The synchronizing system accepts pulses from a mechanical master timing shaft which indicates the mid-points of the breathing cycles. These pulses are applied to the synchronization system which, in response to additional synchronization information on an audio tape, indicates whether the audio signal is early or late with respect to the mechanical system. Accordingly, a voltage controlled oscillator produces an output proportional to the indication to control the tape drive and create synchronization of the audio and mechanical systems.

United States Patent. -1 1 Krause 11 3,769,526 Oct. 30, 1 973 54]SYNCHRONI ZING CIRCUIT [75] Inventor: Irving A. Krause, Nutley, NJ.

[73] Assignee: International Telephone and Telegraph Corporation,Nutley, NJ.

221 Filed: Jan. 31, 1972 21 Appl. No.: 221,902

[52] US. Cl 307/269, 35/17, 307/228,

307/235, 328/151, 328/179 [51 Int. Cl. H03k 5/00, G09b 23/28 [58] Fieldof Search 307/228, 229, 233,

[56] References Cited UNITED STATES PATENTS 2,463,685 3/1949 Fredendallet a1 331/20 2,848,617 8/1958 Horowitz 331/20 2,868,975 'l/1959 Harriset a1. 331/20 X 2,912,651 11/1959 Leeds 331/20 X 3,156,874 11/1964Verdibello 307/228 X 3,375,462 3/1968 McTaggart. 331/20 X COSMOS3,610,952 10/1971 Chandos 307/304 X Primary Examiner-Stanley D. Miller,Jr. Attorney-C. Cornell Remsen, Jr. et a1.

[57] ABSTRACT A manikin synchronization system is described to causerecorded aural sounds to be coincident with mechanical motions includingthe effects of the breathing cycles. The synchronization systeminterfaces with the mechanical and audio systems in order to bring heartsounds, breathing cycles and mechanical motions into time coincidence.The synchronizing system accepts pulses from a mechanical master timingshaft which indicates the midpoints of the breathing cycles. Thesepulses are applied to the synchroniza tion system which, in response toadditional synchronization information on an audio tape,indicateswhether the audio signal is early or late with respect to themechanical system. Accordingly, a voltage controlled oscillator producesan output proportional to the indication to control the tape drive andcreate synchronization of the audio and mechanical systems.

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SYNCHRONHZING CIRCUIT CROSS-REFERENCE TO RELATED APPLICATION Thisapplication is related to application Ser. No. 92,788, filed Nov. 25,1970, and now US. Pat. No. 3,665,087, entitled A Mankin Audio System.The assignee of this referenced application is the same as in thepresent application.

BACKGROUND OF THE INVENTION In general, this invention relates to amanikin synchronizing system which automatically causes the aural soundto be coincident with the mechanical motions including the effects forbreathing.

in order to provide a realistic teaching system for mechanical andacoustic simulation of a large number of heart ailments, the mechanicalsimulation of the manikin must duplicate the breathing and movements ofmajor veins, arteries and motions in the chest areas. Heart sounds foreach ailment are also simultaneously simulated by an audio library oftapes driven in synchronization with the mechanical action. Asillustrated in FIG. 1, a functional block diagram of the teachingmanikin is illustrated. This block diagram is composed of a number ofintegrated subsystems.

In this arrangement, one of a number of diseases to be simulated isselected in control system 11. The control system I 1 may, of course, beadaptable to interface with a central computer. The control systemactivates the necessary switches in the audio library 12 and themechanical subsystem 13. The mechanical subsystem comprises an intricateset of cams, gears, motors, solenoids and relays which provide therealistic mechanical simulation to the manikin.

The audio library consists of a sound reproducing arrangement which willproduce four distinct heart sounds for each heart ailment selected. Thecall-up system 14 may be one of the types described in the crossreferenced application, and provides the proper heart soundcorresponding to the classic chest area being auscultated by theoperator. Insofar as the cross referenced application is necessary foran understanding of the present invention, it is incorporated herein bythe reference.

The synchronization system functions automatically to cause the auralsounds recorded to be coincident with the mechanical motions includingthe effects of the breathing cycle. The synchronization subsystem is thesubject matter of the present invention and will further be describedand explained herein.

SUMMARY OF THE INVENTION It is therefore an object of the presentinvention to provide an improved synchronization system.

Another object of the invention is to provide a synchronization systemfor a manikin which functions automatically to cause recorder sounds tobe coincident with mechanical motion.

According to the broader aspects of the invention, there is provided asynchronization system in which first means is responsive to a firsttiming cycle to produce a first function, second means in the system isresponsive to a second timing cycle to store a sample of said firstfunction, and third means in the system is responsive to the storedsample to produce an output proportional to the sample.

A feature of the invention is to provide a synchronization system for amanikin in which a first means is responsive to a first cycle-indicatinga breathing cycle to produce a first function, a second means isresponsive to a second cycle indicating a cycle of heartbeats to store asample of said first function; and in which third means is responsive tothe stored sample to produce a signal proportional to said sample,whereby said heartbeat cycle is brought into synchronism with saidbreathing cycle. I

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing objects and features ofthe invention will best be understood by reading the followingdescription in connection with the drawings, in which:

FIG. 1 is a functional block diagram of a manikin incorporating thesynchronization system of the invention;

FIG. 2 illustrates an embodiment of a manikin arrangement utilizing thesynchronization system according to the invention; and

FIG. 3 details an embodiment of a synchronization system according tothe invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 2, afunctional embodiment of the manikin arrangement incorporating theprinciple of the invention is illustrated. A 5 MHz oscillator 21furnishes a signal to a metal disc 22 implanted at the end of a specialtype'stethoscope 23 by means of a coaxial cable 24. The four classicalareas of the chest 25 are fitted with conductive rubber portions locatedunder the skin of the manikin 26. Each conductive section is connectedto a recorder call-up track selection arrangement by its own coaxialcable. When the special stethoscope 23 is placed in contact with theskin over a conductive portion, a signal is capacitively induced to oneof the sections 25. This signal closes an appropriate relay to make oneof the contacts 27a-27d for the track selection. Associated with eachcontact 27 is a reading head 28 which couples the heart signalcorresponding to the area ausculated to driver amplifier 29. Theamplifier output passes through a volume control 290 to the transducer30 which emits the audio sound either in the special stethoscope 23and/or to an associated loudspeaker.

The mechanical simulation of pulsing of various veins, arteries andbreathing is operated by a multiple of cams all of which are driven by amaster timing synchronous motor. This arrangement facilitates thealtering of the motions as required by the different heart ailments tobe simulated. Motions are altered by allowing only those cams requiredfor each ailment to be in contact with a cam follower schematicallyillustrated as protruding into the manikin 26. The operation of themechanical simulation and selection is not part of this invention, andis only mentioned in connection with attaining a timing signal ashereinafter described.

The mechanical audio synchronizer 31 interfaces with the mechanical andaudio library systems in order to bring the heart sounds, breathingcycle, and mechanical motions into proper time coincidence.

In order to explain how the synchronizer achieves its objectives, it isnecessary to point out the basic timing cycle of this manikinarrangement. Heartbeats occur at a rate of one per second and abreathing cycle is complated in 5 seconds. The basic timing cycle istherefore one cycle in 5 seconds. By maintaining an integral number ofheartbeats (five) per breathing cycle, the synchronization process issimplified. Once the breathing cycle is brought into synchronism withthe mechanical and audio systems, the heart sounds and motions will alsobe in unison.

The synchronizer 31 accepts pulses from the mechanical master timingshaft 32 by means of timing cam 33 contacts 34. The pulses producedindicate the midpoints of the breathing cycles. These pulses are appliedto a relay in the synchronizer which is used to initiate a rampfunction. The mid-point of the ramp function is to be the correct timefor the first heart sound. An audio tape 35 which contains the heartsounds also contains synchronization information 36a, 36b in the form ofeither pieces of foil as illustrated, or 5 Kl-lz subcarrier pulses whichare located 5 seconds apart and correspond to the first heart sound. Thefive heart sounds 37a-37e on each track occur within one 5- secondbreathing cycle. The synchronization information is read by a signalsensor 38 which is coupled to the synchronizer 31 to cause a relay toclose momentarily in the synchronizer to sample the initiated rampfunction. This produces a measurement in terms of voltage as to whetherthe audio sound is early or late with respect to the mechanicalsimulation system. This sample is held until the next sample comesalong. The sample is applied to a voltage controlled oscillator whosefrequency is nominally 60 Hz at a voltage corresponding to that of themidpoint of the ramp. If the sound is late, the voltage controlledoscillator in the synchronizer 31 is proportionally increased and if itis early, it is proportionally decreased. Therefore, after a few samplesit is in time and continues to run on time at a nominal 60 Hz frequency.The heart sounds follow the-speed of the voltage controlled oscillatorbecause its output signal is now coupled through a power amplifier 39,for example a Bogen type CHB 100, to drive and control the synchronousmotor drive 40 of the tape player.

The synchronizer system 31 parameters permit rapid synchronization. Thetime required for synchronization is random because 'thestart of thetape player is random and synchronization can take any amount of timefrom O to about 25 seconds. Because an endless tape is used, containingan integral multiple of 5 seconds of length, synchronization need takeplace only once each time a disease is changed. Changing of a tape may Ioccur by either replacing a particular tape which may be in the form ofcassettes, or by erasing the tape and rewriting according to a systemsuch as described in the cross referenced application. The acquisitiontime described above will in most instances synchronize a new tapebefore the mechanical system has completed its change to the newselected illness.

Referring now to FIG. 3, a detailed schematic diagram illustrates asynchronizer according to the invention. The coil of relay K1 isconnected to the manikin timing as illustrated in FIG. 2. Its contactsare momen-.

tarily closed according to the breathing cycle established. This causescapacitor C1 to charge and discharge producing a ramp function accordingto the time constant established by capacitor C1 and resistor Rll. Anamplifier A1 is connected as a voltage follower with its labeled pointsconnected as illustrated to produce at its output point A6 a rampvoltage, the reference of the ramp voltage being variable according tothe point set on the variable resistor R2. This set point has beenpreset to the linear portion of the following COSMOS element B1. Theramp function is sampled according to the tape timing synchronizationwhich momentarily closes the contacts of relay K2. Capacitor C2 storesthe voltage sampled, since the time constant provided by C2 and theCOSMOS element B1 is long due to the high impedance of the COSMOS devicewhich is connected as illustrated. Resistor R4 couples the sampled andstored voltage to the amplifier D1 which is connected as an inverting DCbuffer and summer. The mid-point of the ramp function has been set byadjusting the resistive arrangement of R4, R5 and R6. Resistor R7 hasthe same value as R5 to provide a one-to-one gain ratio, so that thesynchronizing arrangement does not overshoot during operation. Thevoltage at point D6 controls the bias on the FET which is coupled by C3to the following voltage controlled oscillator arrangement. The VCOarrangement includes amplifier El and a limiter portion comprising twozener diodes Z1, Z2 and three resistors R8,'R9 and R10 connected asillustrated. The time constant for the oscillator output is determinedby C4 and the F ET which are coupled in parallel with C5 and R11. TheVCO nominally produces for the parameters indicated a 60 Hz output.According to the bias applied from output D6, the FET resistance willvary, and the oscillator frequency output will change in proportion tothe resistance variation caused by the biasing voltage.

The illustrated circuit of FIG. 3 will function as follows. When thecontacts of relay Kl close, Cl will charge to produce the ramp function.Assume that the contacts of relay K2 close too soon before the desiredsynchronization, i.e., a synchronizing point on the tape is detected andK1 momentarily closes. This means that the output voltage at A6 is lowerthan the mid-point of the ramp, and the sampled and stored voltageacross C2 is lower than normal. Then the voltage at B12 is inverted andhigher than normal. This voltage is again inverted and summed, and thebias output voltage at D6 is lower than normal. A lower bias voltagewill provide a higher resistance, and the total time constant of the VCOis increased. The longer time constant will cause a lowering of thefrequency. In a similar manner, on the next cycle the sampling of theramp function will be closer to the preset mid-point, and will continueuntil both the manikin breathing timing cycle and the audio tape cycleare in synchronism. As previously indicated, since the start of the taperecorder is random, synchronism with the components illustrated can takeany amount of time from O to 25 seconds.

In the foregoing a means has been described for synchronizing a selectedsound cycle with the mechanical motion cycle of a manikin. Thesynchronizer includes a means for producing a first function indicatinga mechanical timing cycle, a second means coupled to said first meansfor storing a sample of said first function in response to a selectedsound cycle, and means to provide a voltage output proportional to thesample to cause a voltage variable means to control a subsequentlycoupled voltage controlled oscillator, whereby the output of saidoscillator is proportional to the synchronization required between soundand mechanical cycles.

Although i have described above the principles of my invention inconnection with specific apparatus, it should be clearly understood thatit is by way of example only and not as a limitation on the scope of myinvention as set forth in the objects and features thereof and in theaccompanying claims.

I claim:

1. A synchronizing circuit, the combination comprising:

first means for producing a ramp function representing a first timingcycle including a relay having its contacts momentarily closed accordingto said first cycle,

a first capacitor and resistor coupled to said relay contacts, saidfirst capacitor charging and discharging to produce a ramp functiondetermined by the time constant of said first capacitor and resistor andthe closing of said relay contacts, and I a voltage follower amplifiercoupled to receive said ramp function and produce at its output a rampvoltage;

second means coupled to said first means for storing and sampling saidramp voltage in response to a second timing cycle including a secondrelay having its contacts momentarily closed according to said secondtiming cycle for sampling said ramp voltage, and

a second capacitor coupled to said relay contacts and across a highimpedance device to store the voltage sampled;

third means coupled to said second means to provide a voltage outputproportional to the stored voltage including a third amplifier andresistive means connected as an inverting DC buffer and summer stage toprovide at the amplifier output said proportional voltage; and

fourth means coupled to said third means to effect a synchronizationbetween said first and second timing cycles including an FET biased bysaid proportional output voltage to effect a subsequently coupledoscillator means, the frequency output of which varies in proportion tothe resistance variation of said FET caused by the biasing voltage,whereby a lower bias voltage will increase the total time constant ofthe oscillator means and cause a lowering of the frequency output.

2. The combination of claim 1 including variable resistance meanscoupled between the output of said follower amplifier and said secondrelay contacts, said variable resistance means being used to adjust thereference level of said ramp voltage.

3. The combination of claim l wherein said high impedance device is aCOSMOS element.

4. A circuit to synchronize mechanical motions and electrical signals,the combination comprising:

first means for producing a ramp function representing a firstmechanical motions timing cycle including a relay having its contactsmomentarily closed according to the mechanical motions of said firstcycle,

a first capacitor and resistor coupled to said relay contacts, saidfirst capacitor charging and discharging to produce a ramp functiondetermined by the time constant of said first capacitor and resistor andthe closing of said relay contacts, and

a voltage follower amplifier coupled to receive said ramp function andproduce at its output a ramp voltage;

second means coupled to said first means for storing and sampling saidramp voltage in response to a second electrical signals timing cycleincluding a second relay having its contacts momentarily closedaccording to the electrical signals of said second timing cycle forsampling said ramp voltage,

a second capacitor coupled to said relay contacts and across a highimpedance COSMOS element to store the voltage sampled, and

a variable resistor coupled between the output of said followeramplifier and said second relay contacts, said variable resistor beingused to adjust the reference level of said ramp voltage;

third means coupled to said second means to provide a voltage outputproportional to the stored voltage including a third amplifier andresistive means connected as an inverting DC buffer and summer stage toprovide at the amplifier output said proportional voltage; and

fourth means coupled to said third means to effect a synchronizationbetween said first and second timing cycles including an FET biased bysaid proportional output voltage to effect a subsequently coupledoscillator means, the frequency output of which varies in proportion tothe resistance variation of said FET caused by the biasing voltage,whereby a lower bias voltage will increase the total time constant ofthe oscillator means and cause a lowering of the frequency, and a higherbias voltage will raise the frequency output. I

1. A synchronizing circuit, the combination comprising: first means forproducing a ramp function representing a first timing cycle including arelay having its contacts momentarily closed according to said firstcycle, a first capacitor and resistor coupled to said relay contacts,said first capacitor charging and discharging to produce a ramp functiondetermined by the time constant of said first capacitor and resistor andthe closing of said relay contacts, and a voltage follower amplifiercoupled to receive said ramp function and produce at its output a rampvoltage; second means coupled to said first means for storing andsampling said ramp voltage in response to a second timing cycleincluding a second relay having its contacts momentarily closedaccording to said second timing cycle for sampling said ramp voltage,and a second capacitor coupled to said relay contacts and across a highimpedance device to store the voltage sampled; third means coupled tosaid second means to provide a voltage output proportional to the storedvoltage including a third amplifier and resistive means connected as aninverting DC buffer and summer stage to provide at the amplifier outputsaid proportional voltage; and fourth means coupled to said third meansto effect a synchronization between said first and second timing cyclesincluding an FET biased by said proportional output voltage to effect asubsequently coupled oscillator means, the frequency output of whichvaries in proportion to the resistance variation of said FET caused bythe biasing voltage, whereby a lower bias voltage will increase thetotal time constant of the oscillator means and cause a lowering of thefrequency output.
 2. The combination of claim 1 including variableresistance means coupled between the output of said follower amplifierand said second relay contacts, said variable resistance means beingused to adjust the reference level of said ramp voltage.
 3. Thecombination of claim 1 wherein said high impedance device is a COSMOSelement.
 4. A circuit to synchronize mechanical motions and electricalsignals, the combination comprising: first means for producing a rampfunction representing a first mechanical motions timing cycle includinga relay having its contacts momentarily closed according to themechanical motions of said first cycle, a first capacitor and resistorcoupled to said relay contacts, said first capacitor charging anddischarging to produce a ramp function determined by the time constantof said first capacitor and resistor and the closing of said relaycontacts, and a voltage follower amplifier coupled to receive said rampfunction and produce at its output a ramp voltage; second means coupledto said first means for storing and sampling said ramp voltage inresponse to a second electrical signals timing cycle including a secondrelay having its contacts momentarily closed according to the electricalsignals of said second timing cycle for sampling said ramp voltage, asecond capacitor coupled to said relay contacts and across a highimpedance COSMOS element to store the voltage sampled, and a variableresistor coupled between the output of said follower amplifier and saidsecond relay contacts, said variable resistor being used to adjust thereference level of said ramp voltage; third means coupled to said secondmeans to provide a voltage output proportional to the stored voltageincluding a third amplifier and resistive means connected as aninverting DC buffer and summer stage to provide at the amplifier outputsaid proportional voltage; and fourth means coupled to said third meansto effect a synchronization between said first and second timing cyclesincluding an FET biased by said proportional output voltage to effect asubsequently coupled oscillator means, the frequency output of whichvaries in proportion to the resistance variation of said FET caused bythe biasing voltage, whereby a lower bias voltage will increase thetotal time constant of the oscillator means and cause a lowering of thefrequency, and a higher bias voltage will raise the frequency output.